The ratification process saw difference in opinion on the topic of voluntary resignation from the Union mostly along federalist and anti-federalist lines, with Madison and Hamilton (among others) affirming the idea that the Constitution was incompatible with the idea of secession. (Madison later affirmed that no such Constitutional right existed during the Nullification Crisis in 1832, though the language of the Kentucky and Virginia Resolutions—drafted by Jefferson and Madison respectively—did suggest the right of revolution as opposed to secession.) Critics of the Constitution's consolidation of a federal government, and thus denial of state sovereignty, opposed ratification in part for this reason—Patrick Henry being chief among them. One example of such opposition to the forfeit of sovereignty and the fear of the Constitution's failure to protect states' rights was the issue raised by Anti-Federalists during the New York ratification convention. In response, both Madison and Hamilton affirmed the incompatibility of legal withdrawal from the Union and the Constitution that created it. Hamilton specifically stated, in summarizing a letter Madison had written to him, that ratification required permanent acceptance of loyalty to the Union.

As for how it changed in the future: the debate post-ratification on the nature of secession largely evolved into a conflict between Compact Theory, and those opposed to it. It was effectively a debate over the very nature of the federal government and the states' relation to it, compact theorists favoring the idea that it was, as one could guess, a compact between states, whereas those opposed favored the idea that the authority of the Constitution and the federal government was lastly predicated on the people rather than those states. Daniel Webster's debate with Robert Hayne of SC summarized the nationalistic view, in stating in part the above—that of a "popular government...responsible to the people; and itself capable of being amended and modified, just as the people may choose it should be." This directly conflicted with the idea that the nature of the federation was an association of sovereign states. Madison, in response to Daniel Webster's arguments in debate with Hayne, essentially affirmed his position on the invalidity of secession, while at the same time making the point of distinguishing between the right to secession (which he argued had no constitutional basis) and the right to revolution in the face of considerable oppression (which Madison argued existed as a natural, extraconstitutional right). There had been several attempts otherwise to argue for a legal basis for secession, such as in the argument that the abandonment of the Articles of Confederation constituted a secession from them, setting a precedent for secession in the future. Moreover, some argued that Texas' secession from Mexico did the same. Nevertheless, come 1861, it was ultimately the extraconstitutional right that was mostly invoked in the secession movements, particularly in the Upper South where Lincoln's response to the CSA assault on Fort Sumter spread fear of coercion to stay in the Union and permanently forfeit the perceived right to secession (whereas it had been defeated numerous times between the secession winter of 1860-61 and April 1861). These states, using VA as an example, viewed Lincoln's reaction of calling forth volunteers as a violation of the perceived sovereignty of Southern states, and indirectly a violation of their perceived sovereignty. In the case of the Deep South, the secessionists held that the federal government had encroached on their rights to a point that justified invocation of the right to secession/revolution, though the Unionist viewpoint held that no such action was warranted.

The legal validity of secession was officially resolved by the Chase Court following the ACW, in Texas v. White (1869). The decision ultimately rested upon the idea that Texas had never in truth seceded from the Union, as state revocations of their loyalty to the Union are invalid, the language of the Constitution carrying with it the explicit perpetuity of the Articles of Confederation (i.e. "to form a more perfect Union"—perpetuity being, naturally, the implication of what constitutes a "perfect Union").

Sources:

Freehling, William. The Road to Disunion, vols. 1 and 2.

Madison, James, "Letter to Daniel Webster", (March 1833).

Stampp, Kenneth M. "The Concept of a Perpetual Union". The Journal of American History, 65:1. (1978), 5–33.

Webster, Daniel, "Second Reply to Hayne" (Address before U.S. Senate, 1830).